This year’s award winner is involved in research focusing on the significance of genes in the development of obesity and type 2 diabetes.
The percentage of type 2 diabetes in Greenland has increased dramatically over the past 25 years. Part of the reason lies in the genes. In a study published in the journal Nature in 2014, Niels Grarup, together with other Danish researchers, shows that a specific gene variant considerably increases the risk of type 2 diabetes. The gene variant is only found among Greenlanders and not in the European population. The gene variant is the cause of 15 per cent of all diabetes in Greenland.

“This is because the Inuit in Greenland are descended from people who have lived isolated in the North Atlantic area for thousands of years. During this period, the genetic composition of the Inuit population changed, which can happen relatively quickly and drastically if a population is small and lives isolated from other populations”, says Niels Grarup.

Five percent of the population

The study involves 4 500 Greenlanders, almost five per cent of the total population of about 57 000. The researchers applied advanced technology on the participants’ blood samples in order to chart DNA, which contains all their genes. The method also makes it possible to chart variations in individual genes, and it was a specific variant of the gene TBC1D4, which controls glucose uptake in muscle cells, that particularly attracted the researchers’ attention.

The carriers of the specific gene have impaired glucose uptake in muscle cells, which makes the indivituals insulin-resistant, i.e. the muscles’ capacity to take up nutrients (glucose) after a meal is impaired, leading to increased blood sugar levels and, in the long term, type 2 diabetes.

Almost a quarter of Greenland’s population, 23 per cent, are carriers of the gene variant.

Extremely high risk

If the gene variant is passed on to someone by both of their parents, the risk of developing type 2 diabetes is extremely high. Of the participants in the study, 60 per cent of those who were 40 or older, and had inherited the gene variant from both their mother and father, had developed type 2 diabetes. Among those who were 60 or older, the figure was 80 per cent.

“We know of a number of other gene variants in the European population that also increase the risk of developing diabetes, but this gene variant has a much stronger effect than we have previously seen”, says Niels Grarup.

Ground-breaking research

The price committee motivation:
“This year’s recipient of the Leif C Groop Aard is Niels Grarup of the Novo Nordisk Foundation Centre for Basic Metabolic Research at the University of Copenhagen. His research focuses on genetic variation and type 2 diabetes in which he studies genetic variations and their role in the development of the disease. The Award Committee’s interest was particularly captured by his ground-breaking research on the Inuit population in Greenland. Grarup and his colleagues identified a genetic variation in a protein that is important for insulin signalling, which leads to impaired function and insulin resistance. It is rare that such well-conducted studies have contributed to increased understanding of such importance for the patient.”
Link to the research article: https://www.ncbi.nlm.nih.gov/pubmed/25043022)

Footnote:
In connection with the Diabetes research Day, Niels Grarup will give an award lecture in the Jubilee auditorium in the hospital area of Malmö on 11 February.